Molding apparatus

ABSTRACT

A cavity insert for the injection side and a core insert for the ejection side of a mold are each shaped as a generally cylindrical, stepped body provided with circumferentially extending locking grooves and a liquid cooling or heating channel. Insert retainers and lifters having rotatable elements with locking tongues engaging the locking grooves clamp the inserts in the main mold frame. The main mold frame is provided with liquid conduits opening to opposite ends of the liquid channels so that the need for machining liquid conduits and channels for different inserts is avoided. Ejector tooling may be connected to the core insert for insertion and removal with it. The rotatable elements also have shoulders engageable with the inserts and may be axially moved to lift the inserts partly out of the mold frame to enable rapid changeover from one insert to another. Sliding wedges are used to releasably secure the ejector tooling to the master mold ejector plates. Improved ejector return pin assemblies are disclosed enabling the use of oversized inserts. A guided ejector system is also disclosed.

SUMMARY OF THE INVENTION

This invention relates to improvements in molding apparatus andparticularly injection molding apparatus fo the type used for moldingplastic workpieces. However, this invention may be used for other typesof molding such as die casting.

Molds with removable inserts for mold frames are in use and areespecially valuable for prototype or low production molding needswherein the tooling is changed after relatively short runs. However, theknown molds of this type still require substantial changeover time andthe need exists for an inexpensive mold system requiring minimalchangeover time and machining operations.

An object of this invention is to provide improved quick-changeovercavity inserts for the injection side of mold tooling and similarquick-changeover core inserts for the ejection side. Each insertcomprises a generally cylindrical, stepped body provided with a pair ofcircumferentially extending clamping grooves and a circumferentiallyextending liquid cooling or heating channel. Insert retainers andlifters are provided having rotatable elements with locking tonguesengageable with the locking grooves. The rotatable elements are confinedfor axial movement upon clamp screws so that, with the locking tonguesengaged within the clamping grooves, the clamp screws may be tightenedto the master mold to draw and clamp the inserts thereto.

The rotatable elements also have shoulders which may be positioned inengagement with the inserts for lifting the inserts from the mold frameby unscrewing the clamp screws to enable rapid and safe removal of theinserts. Further, the main mold frame is provided with liquidconnections opening to opposite ends of the liquid channels of theinserts to provide for uniform cooling or heating of the inserts so thatthe need for machinging liquid conduits and channels for differentinserts is avoided. Ejector tooling may be connected to the core insertfor insertion and removal with it. Sliding wedges are used to releasablylock the ejector tooling in place.

Further in accordance with this invention, the sprue bushing plate is soconnected to the master mold frame that it may be removed from theinjection side by first removing the cavity insert to provide access tothe screws that hold the sprue bushing plate, and then taking thebushing plate out through the face of the injection side tooling "A"plate. Thus, removal of the injection side of the master mold from themolding machine is not needed. Accordingly, much time may be saved whenchanging sprue bushing types, such as to extended nozzle bushing plates,or when changing, for example, to hot sprue bushings or to runnerlessmanifolds.

Another object of this invention is to provide improved ejection returnpin assemblies which enable the use of oversized inserts which are notflush with the "A" plate and the "B" plate. The return pin assembliesinclude spring discs or washers which cause the return pins to extendbeyond the face of the "B" plate so that they will nonetheless beengaged by the face of the "A" plate if the inserts are slightlyoversized. In a modification, the face ends of the return pins havetapped holes and extension members are provided which may be secured byscrews engaged in the tapped holes to accomodate even greaterthicknesses of the inserts.

Other objects and advantages will become apparent from the followingdescription and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially-exploded perspective view of injection andejection sides of a master mold made in accordance with this invention.

FIG. 2 is a partially-exploded perspective view of the injection side ofFIG. 1.

FIG. 3 is a front elevational view of the injection side.

FIG. 4 is a cross-sectional view of the injection side. taken alongsection line 4--4 of FIG. 3. The section has been rotated through 90degrees.

FIG. 5 is an enlarged, fragmentary, cross-sectional view taken alongsection line 5--5 of FIG. 3 of a portion of the injection side andparticularly illustrating a locating key and notch.

FIG. 6 is an enlarged, fragmentary, cross-sectional view taken alongsection line 6--6 of FIG. 3 of a portion of the injection side andparticularly illustrating an insert retainer and lifting assembly.

FIG. 7 is an elevational view of an insert retainer and lifter elementforming part of the insert retainer and lifting assembly of FIG. 6.

FIG. 8 is an elevational view of the insert retainer and lifter elementas viewed from the right side of FIG. 7.

FIG. 9 is a top plan view of the lifter element of FIG. 7 as indicatedby the arrows 9--9 thereof.

FIG. 10 is a partially-exploded perspective view of the ejection side ofFIG. 1 and a piece part molded thereby.

FIG. 11 is a cross-sectional view of the ejection side analogous to FIG.4. FIG. 11 also shows, by phantom lines, the outline of the injectionside in operative relation to the ejection side. Some parts out of theplane of the section are not illustrated in FIG. 11 to avoid a confusionof lines.

FIG. 12 is a fragmentary cross sectional view of a portion of theejection side taken on section line 12--12 of FIG. 10.

FIG. 13 is a fragmentary cross sectional view similar to FIG. 12 showinga modification.

FIG. 14 is a fragmentary cross sectional view of another portion of theejection side.

DETAILED DESCRIPTION

As used in this description and the claims that follow, the term "cavityinsert" refers to the insert which is on the injection side of a mastermold and is clamped in fixed relation to the "A" plate and the term"core insert" refers to the insert on the ejection side of the mastermold and is clamped in fixed relation to the "B" plate. Thesedefinitions are believed to be conventional and well understood in theindustry. The cavity insert and the core insert are machined withcavities, cores, or flat faces as required by the configuration of thepiecepart to be produced in the mold chamber formed by the cavity andcore inserts. They may also be provided with multiple cavities or coresfor producing more than one piecepart at a time.

With reference to FIG. 1, this invention is directed to mold apparatuscomprising a master frame, generally designated 10, comprising a first,injection side, generally designated 12, and a second, ejection side,generally designated 14. As shown in FIG. 11, the face of the injectionside 12 abuts agains the face of the ejection side 14 when a moldingoperation takes place. The master frame 10 has an external configurationcommon to many master frames in current use so that it is readily usablewith a conventional injection molding machine (not shown). The manner inwhich the master frame 10 is supported by the molding machine may beentirely conventional and therefore is not described herein. It is to beunderstood that the external configuration of the master frame 10 can beconstructed as needed to accommodate the machine with which it is to beused.

With reference to FIGS. 1-4, the injection frame part 12 comprises agenerally rectangular top clamp plate 16 abutted against the rear faceof a first mold or "A" plate 18. Plates 16 and 18 are bolted together inconventional fashion. Four leader pins 20 having enlarged heads 20A(FIG. 4) trapped between the plates 16 and 18 project from therespective four corners of the face of the "A" plate 18. With continuedreference to FIG. 4, a conventional locating ring 22 and a conventionalsprue bushing plate 24 are bolted to the top clamp plate 16. Ring 22 andplate 24 are also constructed to interfit properly with cooperatingparts of the molding machine with which they are used.

In accordance with the present invention and with reference again toFIGS. 1-4, the injection frame part 12 further comprises a generallycylindrical, cavity insert 26 retained within a generally circular,centrally located, cavity insert-receiving bore or hole 28 in the "A"plate 18. Cavity insert 26 is centered on the center, longitudinallyextending axis of the master frame 10 and has a gate 30 opening from asprue 32 to its exposed face 34.

Cavity insert 26 comprises a solid, one-piece metal body which isstepped along its length to comprise three disc-shaped,longitudinally-adjacent sections, namely a first, largest diameter,locking section 36, a second, intermediate diameter, liquid channelsection 38, and a third, smallest diameter, base section 40. The firstsection 36 extends from the insert face 34 to a shoulder 42 parallel tothe face 34 and has diametrically-opposed flats 44 and 46 and a pair ofcircumferentially-extending locking grooves 48 and 50. Locking groove 48is uppermost and extends from the top of flat 44 to the top of flat 46,whereas locking groove 50 is lowermost and extends from the bottom offlat 44 to the bottom of flat 46.

When the insert 26 is assembled in the "A" plate 18, the shoulder 42rests upon a confronting shoulder 52 formed within the bore 28. Theproper rotary orientation of the insert 26 within the bore 28 isaccurately established by a rectangular key 54 that abuts the flat 44and a rectangular key 56 that abuts the flat 46, the keys 54 and 56being located in accommodating, generally rectangular recesses 58 and60, respectively, within the "A" plate 18 and retained therein by screws62. Further to ensure the proper orientation of the insert 26, alocating key 64 (FIGS. 2 and 5) projects from the middle top part of the"A" plate shoulder 52, into a notch 66 (see FIG. 2) in the middle top ofthe insert 26 extending from the upper locking groove 48 to the insertshoulder 42.

Four insert retainer and lifter assemblies, generally designated 70, arelocated around the outer circumference of the cavity insert 26 and areadapted to clampingly retain the cavity insert 26 in the bore 28 of the"A" plate 18 and further, to lift or jack the cavity insert 26 out ofthe bore 28 to initiate removal of the insert 26 from the "A" plate 18.Four circumferentially-spaced arcuate bores, respectively designated72A, 72B, 72C, and 72D, each of which receives one of the retainer andlifter insert assemblies 70, open to the bore 28 and extend through the"A" plate 18, The arcuate bores are so located that two of the retainerand lifter assemblies 70 are positioned adjacent portions of the lockinggrooves 48 and 50 on one side of the "A" plate 18 and two adjacent theother side. The bores 72A and 72C are mutually diametrically opposed asare the bores 72B and 72D. For reasons which will become apparent, fourtapped holes 74, only one being shown in FIG. 6, extend through the topclamp plate 16 in alignment with respective ones of the arcuate bores72A, 72B, 72C, and 72D. Each tapped hole 74 has an aligned counterbore76 located in the face of the top clamp plate 16 abutting the "A" plate18.

As shown in FIGS. 2 and 6-9, each retainer and lifter assembly 70comprises a generally cylindrical retaining and lifting element,generally designated 80, having a through bore 82, and a counterbore 84at one end thereof, the bore 82 and the counterbore 84 being adapted toreceive the shank 86 and the enlarged head portion 88, respectively, ofa threaded clamp screw 90, which is adapted to be threadedly engagedinto the tapped hole 74 in the top clamp plate 16. The clamp screw 90and the retaining and lifting element 80 are held in mutually assembledrelation by the screw head 88 and a pair of jam nuts 92 such that theretaining and lifting element 80 is rotatable about the axis of theclamp screw 90 and substantially confined for axial movement therewith.

With continued reference to FIGS. 2 and 6-9, each retaining and liftingelement 80 has a slot 94 extending part way around the counterbore 84defining an arcuately extending clamping tongue 96 at the exposed end ofthe retaining and lifting element 80 which is adapted to enter one ofthe locking grooves 48 and 50. In addition, the exposed face of theelement 80 is notched as indicated at 98, so that one may insert ascrewdriver therein and rotate the element 80 relative to its associatedscrew 90 about the axis of the tapped hole 74 so as to move the tongue96 into and out of its associated locking groove 48 or 50. The same endof the element 80 is provided with a flat 100 terminating at a shoulder102 which is coplanar with base of the slot 94.

The shoulder 102 is spaced by substantially 90 degrees from the slot 94so that one may, by inserting the tip of a screwdriver into the notch98, rotate the element 80 so as to cause the tongue 96 to enter one ofthe locking grooves 48 or 50. One may then tighten the screw 90 so as todraw the cavity insert 26 tightly against the top clamp plate 16 and theinsert shoulder 42 tightly against the "A" plate shoulder 52. One theother hand, one may, upon loosening the screw 90, again engage in thenotch 98 by the tip of a screwdriver, and rotate the element 80 so thatthe tongue 96 is removed from its associated locking groove 48 or 50 andbring the shoulder 102 of the element 80 into alignment with the insertshoulder 42. Then, by rotating the screw 90 to partly retract the screw90 from the tapped hole 74, whereupon the jam nuts 92 engage thebackface of the element 80, one may cause the shoulder 102 of theelement 80 to move the cavity insert 26 out of the bore 28 in the "A"plate 18.

In practice, to initiate the removal of the cavity insert 26, one wouldloosen all four of the screws 90 and rotate the elements 80 to removethe clamping tongues 96 from the locking grooves 48 and 50. One wouldthen partly unscrew two diametrically opposed screws 90 in order to drawthe cavity insert 26 an inch or so out of the insert-receiving bore 28.This results because the jam nuts 92, being carried by the screws 90engage the rear face of their respective elements 80, whereupon theshoulders 102 of the latter push against the insert shoulder 42.Thereafter, one may grasp the exposed part of the insert 26 by hand andcompletely remove it. A replacement insert (not shown) may be asssembledin the bore 28 simply by bringing the elements 80 to a uniform level sothat all of the clamping tongues 96 may engage in the clamping groovesof the replacement cavity insert, sliding the replacement cavity insertinto the cavity-receiving bore 28, rotating the elements 80 so thattheir clamping tongues 96 enter the clamping grooves 48 and 50, and thenscrewing the screws 90 deeper into the tapped holes 74 to secure thereplacement cavity insert.

From the foregoing description, it is seen that this invention providesa simple yet reliable mechanism for quickly changing from one cavityinsert to another. At all times the inserts are securely under thecontrol of the person using the equipment so that damage to the insertsor other parts of the molding machine should not occur duringchangeover.

Referring again to FIGS. 2 and 4, the intermediate diameter or liquidchannel section 38 of the cavity insert 26 has a circular outer surface110 of uniform diameter except for a centrally located liquid conduitgroove 112 that extends approximately 340 degrees therearound, theadjacent ends of which are separated by a barrier section 114. Groove112 forms a conduit for water or other liquid that may be used forheating or cooling of the cavity insert 26. To this end, the barrier 114is located at the 3:00 o'clock position when viewing the injection sidefrom its face as in FIG. 3, and the "A" plate 18 is provided with aliquid inlet connector 116 and a liquid outlet connector 118 atapproximately the 3:00 o'clock position that communicate directly withopposite ends of the liquid conduit groove 112. As will be apparent tothose familiar with the art, suitable liquid supply lines, which are notshown but are commonly used, will be connected to the inlet 116 and theoutlet 118 for circulating cooling or heating liquid, usually water,around the cavity insert 26.

To insure that there is no leakage of liquid from the center section 38,a first, larger diameter, O-ring sealing member 120, which bears againstthe insert shoulder 42, encircles the intermediate section 38 and islocated within a hollow annular ring 122 machined in the insert 26 andthe insert-receiving bore 28 for this purpose. Further, a second,smaller diameter O-ring sealing member 124 encircles the smallestdiameter section 40 of the cavity insert 26 and bears against a shoulder126 formed on the intermediate insert section 38 adjacent and radiallyoutwardly extending from the smallest diameter insert section 40.

The base surface, designated 128, of the smallest diameter insertsection 40 bears against the confronting face of the sprue bushing plate24, and is clamped thereto by the retainer and lifter assemblies 70 asdescribed above.

It is thus seen that the task of designing and machining of heating orcooling lines and the need for providing seals, as usually required whenmaking molds, may be avoided by the practice of this invention.

Another advantage of the construction of the cavity side 12 is that notonly the cavity insert 26 but also the sprue bushing plate 24 may beremoved from the face side of the "A" plate 18 without removing theinjection side of the master mold from the molding machine. Accordingly,much time may be saved when changing sprue bushing types, such as toextended nozzle bushing plates, or when changing, for example, to hotsprue bushings or to runnerless manifolds.

Turning now to FIGS. 1, 10, and 11, the ejector side 14 comprises aU-frame 140, a support plate 142, a "B" plate 144, main frame ejectorplates 146 and 148, and ejector extension blocks 150. Alignment bushings152 at the corners of the "B" plate 144 are provided to receive theleader pins 20. The construction and operation of the above ejector sideparts will be apparent to those familiar with the art. Except forfeatures described below, these parts are conventional and furtherdiscussion thereof is deemed unnecessary.

In this case, the "B" plate 144 is provided with a core insert 154,which is adapted to be clamped into a core insert-receiving bore or 155in the "B" plate 144, and which is identical to the cavity insert 26except for differences required to accomodate the ejector mechanism andby the construction of the part to be molded. Core insert 154accordingly comprises a stepped, cylindrical body member, having alarger diameter locking section 156 with flats 158 which cooperate withrectangular keys 160 which are identical to the keys 54 and 56 describedabove. Locking section 156 also has upper and lower locking grooves 162and 164 that correspond fully to the locking grooves 48 and 50 of thecavity insert 26. Four insert retainer and lifting assemblies 166 areused to clamp the core insert to the "B" plate 144, the assemblies 166being identical to the previously described assemblies 70, and havingclamp screws 167 that are threadedly received in tapped holes (notshown) in the support plate 142. Likewise, the core insert 154 has aliquid channel section 168 to which liquid is supplied by connectors 170and 172, and which is jacketed by O-ring sealing members 174 and 176,again the same as in the case of the cavity insert 26. A pin 178 on the"B" plate 144 and a notch 180 in the core insert 154 assure properalignment between the core insert 154 and the "B" plate 144.

With respect to the part to be molded, a simple example is designated182 in FIG. 10, for which the face, designated 184, of the core insert154 has a cavity 186 conforming to the shape of the top and sidewalls ofthe piecepart 182, its bottom being shaped by the face 34 of the cavityinsert 26. To eject the piecepart 182 from the cavity 186, the coreinsert 154 ejector tooling, generally designated 190, is connected inaxial alignment with the core insert 154. Ejector tooling 190 comprisesa pair of ejector tooling plates, namely a rearward tooling plate 192and and a forward tooling plate 194 secured in face-to-face relationshipto one another as by screws 196 (only one of which is shown in FIG. 11).The ejector tooling 190 is preferably connected to the core insert 154so that it will be retained with the core insert 154 when the coreinsert 154 is inserted or removed from the main frame. For this purpose,the ejector tooling plates 192 and 194 are slidably mounted on a pair ofretainer screws 198 which are threadedly engaged in tapped holes in therear of the core insert 154. Retainer screws 198 are slidably receivedin bores 200 in the ejector tooling plates 192 and 194 and have largerdiameter heads 202 located in counterbores 204 in the rear face of therearward plate 192. Because the ejector tooling plates 192 and 194 arefreely slidable relative to the retainer screws 198, the retainer screwsdo not interfere with the operation of the ejector assembly 190, but areeffective to retain the ejector tooling 190 with the insert 154 when itis removed from the main frame tooling.

A pair of ejector pins 206 having heads 208 trapped between the ejectortooling plates 192 and 194 extend through bores 210 in the core insert154 to the base surface, designated 212, of the cavity 186. The ejectorpins may be received in bores 214 in a core pin-retainer plate 216 thatmay be optionally mounted on the rear face of the core insert 154 as bybolts 218. As those familiar with the art will be aware, plate 216 isused to retain core pins (not shown) when such are used.

Of course, it should be understood that the ejector pin arrangementshown in the drawings is merely exemplary of many ejector arrangementsthat may be employed in the practice of this invention and that thearrangement selected will depend upon the demands of the pieceparts tobe produced and the preferences of the mold maker. Those familiar withthe art will recognize that sleeve-type ejectors could be used by addingtwo more plates. Support pillars may be added if the mold maker shoulddesire.

As shown in FIG. 11, the ejector tooling plates 192 and 194 are locatedwithin centrally located botes 220 and 222, respectively, in the masterframe ejector plates 146 and 148. The outer surface of the rearwardtooling plate 146 has a reduced diameter forward section 224 and arearwardly and outwardly sloping intermediate section 226. Thesesurfaces 224 and 226 are adapted to be clampingly engaged by a pair ofwedge-shaped ejector clamps 228 and 230 slidably mounted in transverselyextending guideways 232 and 234 formed in the sides of the master frameejector plates 146 and 148. Each ejector clamp 228 and 230 has anassociated clamping screw 236 affixed thereto as by the enlarged head,designated 238, thereof and a snap ring 240. The clamping screws 236 arethreadedly engaged in tapped holes 242 in the ejector plate 146.

The ejector side is prepared to mold the piecepart 182 by positioningthe core insert 154 and its associated ejector tooling into the ejectorframe assembly. The retainer and lifter assemblies 166 are tighteneddown, just as in the case of the retainer and lifter assemblies 70, todraw the core insert 154 into the "B" plate 144 and clamp it thereto.The transversely slidable ejector clamp is then tightened so as tosecure the ejector tooling plates 192 and 194 to the master frameejector plates 146 and 148. Removal of the core insert and ejectortooling may be accomplished by first withdrawing the ejector clamps 228and 230 from clamping engagement with the ejector tooling plates 192 and196 by unscrewing the clamp screws 236. The core insert 154 may then bejacked out of the "B" plate 144 by operation of the retainer and lifterassemblies 166 in exactly the same manner as the cavity insert 26 isjacked out of the "A" plate 18 by the retainer and lifter assemblies 70.

Some mold makers may prefer not to connect the core insert 154 to theejector tooling 190 by the retainer screws 198. In such event, ofcourse, the ejector tooling 190 may be installed and removed separatelyfrom the core insert 154.

It may be noted that all of the screws used to tighten or loosen theretainer and lifter assemblies 70 and 166 and the ejector clamps 236 and238 have conveniently accessible socket heads so that a skilled workmanmay completely change over from the molding of one piecepart to anotherin a matter of a few minutes. It may also be noted that the machining ofinserts is vastly simplified in contrast to usual practice because thebasic shape of the inserts is retained from piecepart to piecepart, onlythe shapes of the cores and cavities needing to be custom machined.

The return of the ejector assembly 190 in preparation for eachsubsequent molding operation may be assured, as in conventional, by theuse of ejector return pins connected to the main frame ejector plates146 and 148. In operation, the face of the "A" plate engages the ends ofthe ejector return pins as the mold begins to close in preparation foreach molding operation, thus forcing the return of the ejectormechanism. Preferably, an improved return pin assembly, generallydesignated 250, and illustrated in FIG. 12, is employed with the cavityand core inserts of this invention. The assembly 250 includes fourreturn pins 252 (see FIG. 1), one of which is shown in FIG. 12. The pin252 has an enlarged head 254 trapped between the main frame ejectorplates 146 and 148 in a recess provided therefore. A spring disk orwasher 256 is located in the recess between the return pin head 254 andthe rearward ejector plate 146. The spring disk or washer 256 biases theejector pin 252 outwardly past the face of the "B" plate 144, preferablyby approximately 0.020 inch. Accordingly, it is possible to form eachinsert 26 and 154 with an oversized thickness so that they projectbeyond the planes of the faces of the "A" plate 18 and "B" plate 144,respectively, by as much as 0.010 inch. This enables the moldmanufacturer to machine the inserts so that a few thousandths of an inchmay be machined off after the machined surfaces of the inserts havebecome worn through use.

The face ends of the ejector return pins 252 are preferably providedwtih tapped, axially extending holes 258 so that the ejector return pins252 may be modified, as illustrated in FIG. 13, to include axiallyextending extension sleeves 260 held thereto by socket head screws 262.Thus, the mold maker may machine inserts which are quite oversized sothat the "A" plate and the "B" plate are mutually spaced by as much asan inch or more during each molding operation. In such case, the face ofthe "B" plate will engage the free end of the return pin extensions toassure return of the ejector mechanism.

The practice of this invention enables the use of a guided ejectionsystem as part of the main mold frame. Referring to FIG. 14, a pair ofguide pins 270, only one being shown, are press fit at a suitablelocation in the U-frame 140 and slidably received by a guide bushing 272clamped to the main frame ejector plates 146 and 148 to provide apositive guide for the ejector mechanism. Therefore, it is unnecessaryto provide a guide means for each core insert ejector tooling assembly.

Although the preferred embodiment of this invention has been described,it will be apparent that various modifications may be made within thepurview of the following claims.

I claim:
 1. Molding apparatus comprising:an injection side having a maininjection side frame with an "A" plate having at least one exposed faceand a cavity insert-receiving hole extending through said "A" plateopening to its said exposed face, said injection side further having acavity insert adapted to fit within said cavity insert-receiving hole,and cavity insert retainer and lifter means manipulable from saidexposed face for clamping said cavity insert to said "A" plate and forlifting said cavity insert partly out of said cavity insert-receivinghole without disassembly of said injection side; and an ejection sidehaving a main ejection side frame with a "B" plate having at least oneexposed face and a core insert-receiving hole extending through said "B"plate opening to its said exposed face, said ejection side furtherhaving a core insert adapted to fit within said core insert-receivinghole, and core insert retainer and lifter means manipulable from saidexposed face of said "B" plate for clamping said core insert to said "B"plate and for lifting said core insert partly out of said coreinsert-receiving hole without disassembly of said ejection side.
 2. Themolding apparatus of claim 1 wherein said injection side has a tappedhole, and wherein said cavity insert has locking groove means forminglocking groove segments at peripheral portions thereof, and wherein saidcavity insert retainer and lifter means includes a cavity insertretaining and lifting assembly including a screw threadedly engaged insaid tapped hole, a cavity insert retaining and lifting elementrotatable about the axis of said screw, and means for confining saidelement for axial movement with said screw, said retaining and liftingelement having a locking tongue adapted to enter said locking groovemeans for clamping said cavity insert to said "A" plate upon tighteningof said screw.
 3. The molding apparatus of claim 2 wherein said cavityinsert retaining and lifting element further has a shoulder that may, byrotation of said element, be moved into alignment with a part of saidcavity insert for engaging and lifting said cavity insert partly out ofsaid cavity insert-receiving hole upon loosening of said element bypartial retraction of said screw from said tapered hole.
 4. The moldingapparatus of claim 1 wherein said injection side has a tapped hole, andwherein said cavity insert retainer and lifter means includes a cavityinsert retaining and lifting assembly including a screw threadedlyengaged with said tapped hole, a cavity insert retaining and liftingelement rotatable about the axis of said screw, and means for confiningsaid element for axial movement with said screw, said insert retainingand lifting element having a shoulder that may, by rotation of saidelement, be aligned with a part of said cavity insert for engaging andlifting said cavity insert partly out of said cavity insert-receivinghole by partial retraction of said screw from said tapped hole.
 5. Themolding apparatus of claim 1 wherein said cavity insert comprises agenerally cylindrical, one-piece body stepped along its length tocomprise longitudinally-adjacent sections including a liquid channelsection having a liquid channel groove extending substantiallycompletely therearound and interrupted by a barrier adjacent each endthereof, wherein a pair of axially spaced O-ring seals are located onopposite sides of said groove, and wherein said "A" plate has liquidconnections in communication with said ends of said groove.
 6. Themolding apparatus of claim 1 wherein said ejection side has a tappedhole, and wherein said core insert has locking groove means forminglocking groove segments at peripheral portions thereof, and wherein saidcore insert retainer and lifter means includes a core insert retainingand lifting assembly including a screw threadedly engaged in said tappedhole, a core insert retaining and lifting element rotatable about theaxis of said screw, and means for confining said element for axialmovement with said screw, said retaining and lifting element having alocking tongue adapted to enter said locking groove means for clampingsaid core insert to said "B" plate upon tightening of said screw.
 7. Themolding apparatus of claim 6 wherein said core insert retaining andlifting element further has a shoulder that may, by rotation of saidelement, be moved into alignment with a part of said core insert forengaging and lifting said core insert partly out of said coreinsert-receiving hole upon loosening of said element by partialretraction of said screw from said tapped hole.
 8. The molding apparatusof claim 1 wherein said ejection side has a tapped hole, and whereinsaid core insert retainer and lifter means includes a core insertretaining and lifting assembly including a screw threadedly engaged withsaid tapped hole, a core insert retaining and lifting element rotatableabout the axis of said screw, and means for confining said element foraxial movement with said screw, said insert retaining and liftingelement having a shoulder that may, by rotation of said element, bealigned with a part of said core insert for engaging and lifting saidcore insert partly out of said core insert-receiving hole by partialretraction of said screw from said tapped hole.
 9. The molding apparatusof claim 1 wherein said core insert comprises a generally cylindrical,one-piece body stepped along its length to compriselongitudinally-adjacent sections including a liquid channel sectionhaving a liquid channel groove extending substantially completelytherearound and interrupted by a barrier adjacent each end thereof,wherein a pair of axially spaced O-ring seals are located on oppositesides of said groove, and wherein said "B" plate has liquid connectionsin communication with said ends of said groove.
 10. The moldingapparatus of claim 1 wherein said main ejection side frame furthercomprises a pair of ejector plates, an ejector tooling assemblycomprising at least one ejector tooling plate having a sloping surface,and wedge means confined by said ejector plates and engaging saidsloping surface for releasably clamping said ejector tooling assembly tosaid ejector plates.
 11. The molding apparatus of claim 10 furthercomprising means retaining said ejector assembly with said core insertwhen said core insert is removed form said "B" plate.
 12. The moldingapparatus of claim 1 wherein each of said injection side and saidejection side has plural tapped holes, and wherein each of said insertshas locking means forming groove segments at peripheral portionsthereof, and wherein each of said insert retainer and lifter meanscomprises plural insert retaining and lifting assemblies each includinga screw threadedly engaged in one of said tapped holes, an insertretaining and lifting element rotatable about the axis of said screw,and means confining said element on said screw, said retaining andlifting element having a locking tongue adapted to enter said lockinggroove means for clamping its associated said insert to its associatedone of said "A" plate or "B" plate by tightening said screw.
 13. Theapparatus of claim 12 wherein said injection side frame includes asupport plate for said "A" plate and said ejection side frame includes asupport plate for said "B" plate, and wherein said tapped holes are insaid support plates.
 14. The molding apparatus of claim 12 wherein eachof said insert retaining and lifting elements further has a cut awayportion terminating in a shoulder that may, by rotation of said element,be moved into alignment with a part of its associated said insert forengaging and lifting its associated said insert partly out of saidinsert-receiving hole upon loosening of said element by partialretraction of said screw.
 15. The molding apparatus of claim 14 whereinan exposed face of each of said insert retaining and lifting elements isnotched so that one may engage said notch by a simple tool to rotatesaid element selectively to position said locking tongue or saidshoulder in axial alignment with a part of its associated said insert.16. The molding apparatus of claim 15 wherein said locking tongue ofeach of said insert retaining and lifting elements is located betweenthe exposed face thereof and a slot spaced from said exposed face bysaid locking tongue, and wherein said shoulder is coplanar with the baseof said slot.
 17. Molding apparatus comprising: an injection side havinga main injection side frame with an "A" plate having at least oneexposed face and a cavity insert-receiving hole extending through said"A" plate opening to its said exposed face, said injection side furtherhaving a cavity insert adapted to fit within said cavityinsert-receiving hole, and cavity insert retainer and lifter meansmanipulable from said exposed face for clamping said cavity insert tosaid "A" plate and for lifting said cavity insert partly out of saidcavity insert-receiving hole without disassembly of said injection side.18. The molding apparatus of claim 17 wherein said injection side has atapped hole, and wherein said cavity insert has locking groove meansforming locking groove segments at peripheral portions thereof, andwherein said cavity insert retainer and lifter means includes a cavityinsert retaining and lifting assembly including a screw threadedlyengaged in said tapped hole, a cavity insert retaining and liftingelement rotatable about the axis of said screw, and means for confiningsaid element for axial movement with said screw, said retaining andlifting element having a locking tongue adapted to enter said lockinggroove means for clamping said cavity insert to said "A" plate upontightening of said screw.
 19. The molding apparatus of claim 18 whereinsaid cavity insert retaining and lifting element further has a shoulderthat may, by rotation of said element, be moved into alignment with apart of said cavity insert for engaging and lifting said cavity insertpartly out of said cavity insert-receiving hole upon loosening of saidelement by partial retraction of said screw from said tapped hole. 20.The molding apparatus of claim 17 wherein said injection side has atapped hole, and wherein said cavity insert retainer and lifter meansincludes a cavity insert retaining and lifting assembly including ascrew threadedly engaged with said tapped hole, a cavity insertretaining and lifting element rotatable about the axis of said screw,and means for confining said element for axial movement with said screw,said insert retaining and lifting element having a shoulder that may, byrotation of said element, be aligned with a part of said cavity insertfor engaging and lifting said cavity insert partly out of said cavityinsert-receiving hole by partial retraction of said screw from saidtapped hole.
 21. The molding apparatus of claim 17 wherein said cavityinsert comprises a generally cylindrical, one-piece body stepped alongits length to comprise longitudinally-adjacent sections including aliquid channel section having a liquid channel groove extendingsubstantially completely therearound and interrupted by a barrieradjacent each end thereof, wherein a pair of axially spaced O-ring sealsare located on opposite sides of said groove, and wherein said "A" platehas liquid connections in communication with said ends of said groove.22. The molding apparatus of claim 17 wherein said injection side hasplural tapped holes, and wherein said insert has locking means forminggroove segments at peripheral portions thereof, and wherein said insertretainer and lifter means comprises plural insert retaining and liftingassemblies each including a screw threadedly engaged in one of saidtapped holes, an insert retaining and lifting element rotatable aboutthe axis of said screw, and means confining said element on said screw,said retaining and lifting element having a locking tongue adapted toenter said locking groove means for clamping its associated said insertto said "A" plate by tightening said screw.
 23. The apparatus of claim22 wherein said injection side frame includes a support plate for said"A" plate and wherein said tapped holes are in said support plate. 24.The molding apparatus of claim 22 wherein each of said insert retainingand lifting elements further has a cut away portion terminating in ashoulder that may, by rotation of said element, be moved into alignmentwith a part of its associated said insert for engaging and lifting itsassociated said insert partly out of said insert-receiving hole uponloosening of said element by partial retraction of said screw.
 25. Themolding apparatus of claim 24 wherein an exposed face of each of saidinsert retaining and lifting elements is notched so that one may engagesaid notch by a simple tool to rotate said element selectively toposition said locking tongue or said shoulder in axial alignment with apart of its associated said insert.
 26. The molding apparatus of claim25 wherein said locking tongue of each of said insert retaining andlifting elements is located between the exposed face thereof and a slotspaced from said exposed face by said locking tongue, and wherein saidshoulder is coplanar with the base of said slot.
 27. Molding apparatuscomprising: an ejection side having a main ejection side frame with asupport plate and a "B" plate having at least one exposed face and acore insert-receiving hole extending through said "B" plate opening toits said exposed face, said ejection side further having a core insertadapted to fit within said core insert-receiving hole, and core insertretainer and lifter means manipulable from said exposed face forclamping said core insert to said "B" plate and for lifting said coreinsert partly out of said core insert-receiving hole without disassemblyof said ejection side.
 28. The molding apparatus of claim 27 whereinsaid ejection side has a tapped hole, and wherein said core insert haslocking groove means forming locking groove segments at peripheralportions thereof, and wherein said core insert retainer and lifter meansincludes a core insert retaining and lifting assembly including a screwthreadedly engaged in said tapped hole, a core insert retaining andlifting element rotatable about the axis of said screw, and means forconfining said element for axial movement with said screw, saidretaining and lifting element having a locking tongue adapted to entersaid locking groove means for clamping said core insert to said "B"plate upon tightening of said screw.
 29. The molding apparatus of claim28 wherein said core insert retaining and lifting element further has ashoulder that may, by rotation of said element, be moved into alignmentwith a part of said core insert for engaging and lifting said coreinsert partly out of said core insert-receiving hole upon loosening ofsaid element by partial retraction of said screw from said tapped hole.30. The molding apparatus of claim 27 wherein said ejection side has atapped hole, and wherein said core insert retainer and lifter meansincludes a core insert retaining said lifting assembly including a screwthreadedly engaged with said tapped hole, a core insert retaining andlifting element rotatable about the axis of said screw, and means forconfining said element for axial movement with said screw, said insertretaining and lifting element having a shoulder that may, by rotation ofsaid element, be aligned with a part of said core insert for engagingand lifting said core insert partly out of said core insert-receivinghole by partial retraction of said screw from said tapped hole.
 31. Themolding apparatus of claim 27 wherein said core insert comprises agenerally cylindrical, one-piece body stepped along its length tocomprise longitudinally-adjacent sections including a liquid channelsection having a liquid channel groove extending substantiallycompletely therearound and interrupted by a barrier adjacent each endthereof, wherein a pair of axially spaced O-ring seals are located onopposite sides of said groove, and wherein said "B" plate has liquidconnections in communication with said ends of said groove.
 32. Themolding apparatus of claim 27 wherein said main ejection side framefurther comprises a pair of ejector plates, an ejector tooling assemblycomprising at least one ejector tooling plate having a sloping surface,and wedge means confined by said ejector plates and engaging saidsloping surface for releasably clamping said ejector tooling assembly tosaid ejector plates.
 33. The molding apparatus of claim 32 furthercomprising means retaining said ejector assembly with said core insertwhen said core insert is removed from said "B" plate.
 34. The moldingapparatus of claim 27 wherein said ejection side has plural tappedholes, and wherein said insert has locking means forming groove segmentsat peripheral portions thereof, and wherein said insert retainer andlifter means comprises plural insert retaining and lifting assemblieseach including a screw threadedly engaged in one of said tapped holes,an insert retaining and lifting element rotatable about the axis of saidscrew, and means confining said element on said screw, said retainingand lifting element having a locking tongue adapted to enter saidlocking groove means for clamping its associated said insert to said "B"plate by tightening said screw.
 35. The apparatus of claim 34 whereinsaid ejection side frame includes a support plate for said "B" plate andwherein said tapped holes are in said support plate.
 36. The moldingapparatus of claim 34 wherein each of said insert retaining and liftingelements further has a cut away portion terminating in a shoulder thatmay, by rotation of said element, be moved into alignment with a part ofits associated said insert for engaging and lifting its associated saidinsert partly out of said insert-receiving hole upon loosening of saidelement by partial retraction of said screw.
 37. The molding apparatusof claim 36 wherein an exposed face of each of said insert retaining andlifting elements is notched so that one may engage said notch by asimple tool to rotate said element selectively to position said lockingtongue or said shoulder in axial alignment with a part of its associatedsaid insert.
 38. The molding apparatus of claim 37 wherein said lockingtongue of each of said insert retaining and lifting elements is locatedbetween the exposed face thereof and a slot spaced from said exposedface by said locking tongue, and wherein said shoulder is coplanar withthe base of said slot.
 39. Molding apparatus comprising:an injectionside having a main injection side frame with an "A" plate having anexposed face and a cavity insert-receiving hole extending through said"A" plate opening to its said exposed face, said injection side furtherhaving a cavity insert adapted to fit within said cavityinsert-receiving hole, and cavity insert retainer and lifter meansmanipulable from said exposed face for clamping said cavity insert tosaid "A" plate and for lifting said cavity insert partly out of saidcavity insert-receiving hole without disassembly of said injection side;and an ejection side having a main ejection side frame with a pair ofejection plates and with a "B" plate having an exposed face thatconfronts said exposed face of said "A" plate and a coreinsert-receiving hole extending through said "B" plate opening to itssaid exposed face, said ejection side further having a core insertadapted to fit within said core insert-receiving hole, core insertretainer and lifter means manipulable from said exposed face of said "B"plate for clamping said core insert to said "B" plate and for liftingsaid core insert partly out of said core insert-receiving hole withoutdisassembly of said ejection side; and ejection return pin means whichenable the use of said cavity insert and said core insert which aresized to prevent engagement of the face of said "A" plate with the faceof said "B" plate during a molding operation, said ejection return pinmeans comprising an ejection return pin having a free end extendingthrough a bore in said "B" plate and having an enlarged head trapped bysaid ejection plates, and a spring washer between said enlarged head andthat one of said ejection plates which is most remote from said face ofsaid "B" plate and biasing said ejection return pin so that said freeend extends past said face of said "B" plate.
 40. The molding apparatusof claim 39 wherein said free end has a axially extending tapped hole,and wherein said ejection return pin means further comprises anextension sleeve mounted on said free end.
 41. Molding apparatuscomprising:an injection side having a main injection side frame with atop clamp plate, a locating ring connected to the rear of said top clampplate, a sprue bushing plate connected to said locating ring, and an "A"plate having at least one exposed face and a cavity insert-receivinghole extending through said "A" plate opening to its said exposed faceand connected to said top clamp plate, said injection side furtherhaving a cavity insert adapted to fit within said cavityinsert-receiving hole, and cavity insert retainer and lifter meansmanipulable from said exposed face for clamping said cavity insert tosaid "A" plate and for lifting said cavity insert partly out of saidcavity insert-receiving hole without disassembly of said injection side,said sprue bushing plate being removable through said cavityinsert-receiving hole following removal of said cavity insert.
 42. Foruse with a cavity or core insert for an injection molding machine, saidinsert having a locking groove, an insert retaining and lifting assemblycomprising: a threaded clamp screw, a generally cylindrical retainingand lifting element having a through bore, said through bore having acounterbore at one end thereof, means holding said screw and saidelement in mutually assembled relation so that said body is rotatableabout the axis of said clamp screw and substantially confined for axialmovement therewith, said retaining and lifting element having a slotextending part way around said counterbore defining an arcuatelyextending clamping tongue at one end of said retaining and liftingelement, said end of said element being notched, said end of saidelement having a cut away portion terminating at a shoulder which iscoplanar with the base of said slot and arcuately spaced from said slotso that one may, by engaging said notch by a simple tool, rotate saidelement so as to cause said tongue to move into and out of said lockinggroove.
 43. The insert retaining and lifting assembly of claim 42wherein said cut away portion is a flat spaced 90 degrees from saidslot.